Control mechanism for sliding camera shutters



G. N. SMITH 2,553,015

CONTROL MECHANISM FOR SLIDING CAMERA SHUTTERS l0 Sheets-Sheet .1

May 15, 1951 Filed June 16, 1947 m 1/5 7 E 2 i w @q llllill llllllilINVENTOR. Gore/on Smf H7 May 15, 1951 G. N. SMITH CONTROL MECHANISM FORSLIDING CAMERA SHUTTERS l0 Sheets-Sheet 2 Filed June 16, 1947 n lllllllll 400 I INK. l

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10 Sheets-Sheet 3 G. N. SMITH CONTROL MECHANISM FOR SLIDING CAMERASHUTTERS May 15, 1951 Filed June 16, 1947 INVENTOR- Gor'don N. Smith BYAttorney y 1951 G. N. SMITH 2,553,015

CONTROL MECHANISM FOR SLIDING 0mm. SHUTTERS FiledJune 16, 1947 r 10Sheets-Sheet 4 INVENTOR. Gordon N. Sm! H2 BY am Aff rney a. N. SMITH May15, 1951 CONTROL MECHANISM FOR SLIDING CAIIHRA SHUTTERS Filed June 16,1947 INVENTOR. Gor'olon N. Smith 10 Sheets-Sheet 5 Af'iorneg May 15,1951 G. N. SMITH CONTROL MECHANISM FOR SLIDING CAMERA SHUTTERS FiledJune 16, 1947 10 Sheets-Sheet 8 Gordoh \Smil BY? IN VEN TOR.

h @JM Aiiorme y 1951 G. N. SMITH 2,553,015

CONTROL MECHANISM FOR SLIDING CAMERA SHUTTERS l/l I 5 I8 I 2 I 5 F 9 G.N. SMITH May 15, 1951 CONTROL I IECHANISM FOR SLIDING GAMER SHUTTERSFiled June 16, 1947 1o Sheets-Sheet lO INVENTOR.

L w m 6 w N W .m H d/A P @(Q Patented May 15, 1951 CONTROL MECHANISM FORSLIDING CAMERA SHUTTERS Gordon N. Smith, Portland, reg., assignor. toStereocraft Engineering (10., Portland, Oreg.,

a partnership Application June 16, 1947, Serial No. 754,961

Claims.

The present invention relates to the art of photography and has to dowith various refinements and improvements in operating mechanismsforming portions of a highly adaptable camera. The present applicationdiscloses a stereoscopic camera having a pair of lenses but it will beappreciated from the following description that portions of the hereindisclosed invention-may be utilized in a camera having a single set oflenses for taking ordinary pictures.

One of the objects of the invention is to provide ashutter camera with acontinuously adjustable exposure speed range covering a Wide selectionof exposure; speeds, the continuousadjustment offering an infinitenumber of exposure speeds which are readily selectable by a singleadjusting member.

A further object of the present invention is to; provide a camera; witha fixedhigh speed exposure selecting means to permit exposures at afixed speed higher than any included in the continuously adjustablerange.

Another object of the present invention is to provide-a camera with afixed low speed 8X7 posure selecting means to permit exposures at afixed speed slower than any included in the continuously adjustablerange.

Another object of the present invention is to provide means forpermittin the camera to take variable manually controlled timeexposures.

Another object of the present invention is to provide, in one selectingmechanism, means for causing the camera to take pictures at a fixed highspeed, selectable intermediate speeds, a fixed slow speed, or manuallycontrolled time exposures.

Another object of the present'invention isto couple a shutter timer, asdiscussed above, to a guillotine type shutter having a pair of shutterblades for controlling the passage of light from the lens to the film,in which the blades do not liebetween the lens elements. By reason ofthis construction the lens assembly is more easily manufactured, and therelationship of the various elements of the lens assembly is moreaccurately maintainable.

Another object of the present invention is to couple a shutter timer, asdisclosed above, to a switch which may be placed in a photo-flash lampcircuit to insure accurate synchronization of the switch and shutterblades for photo-flash operation.

Another object of the present invention is to couple a shutter timer andsynchro-switch in such a manner that the operation of the shutterrelease mechanism by the operator has no effect on the switchsynchronization, thus eliminating the necessity for the photographerlearning to maintain uniform actuation of the shutter release button.

Another object of the present invention is to construct a shutter timerand other mechanism in a compact arrangement positionable within thebody of the camera in the space between the lens and the plane of thefilm.

Another object of the present invention is to provide a shutter timer,as disclosed above, with a calibrated exposure speed dial lyin in ahorizontal plane and visible at the upper surface of the camera.-

Another object of the present invention is to construct shutter timingmechanisms and other camera mechanisms so as to be positionablein thespace between the two light tunnels in a stereoscopic camera.

Another object of the present invention is to simplify shutter timerescapement mechanism by transforming the approximately translatorymotion of a, driving member to rotary motion for driving an escapementgear train.

Another object of the present invention is to simplify shutter timermechanism by usin a floating'lever having movable ends and anadjustable. fulcrum near its center.

Another object of the present invention is to prevent shutter bounce ina guillotine shutter by causing the shutter blades, after an exposuremovement, to strike'pads so designed'that the shutter blades, althoughadjacent each other, do not strike the same pad. Stated in anothermanner, an object of the present invention is substantially to eliminateshutter bounce in a camera.

Another object of the present invention is to design a photo-flashswitch synchronizing mechanism in such manner as to eliminate the use ofpi tails for conducting the current.

A further object of the present invention is to insure that all lostmotion and backlash which might contribute to erratic shutter timing beeliminated by having the escapement mechanism in motion before releasingthe primary shutter blade to admit light to the film.

A further object of the present invention is to maintain acommonstarting position fora shutter blade timer mechanism regardless ofthe time, interval adiustent in order to simplify synchro-switchcoupling, and to insure maximum drivin tension from the escapementspring.

Another object of the present invention is to position shutter bladelatches for most efficient coupling to guillotine type shutter blades.

Another object of the present invention is to provide means for latchingboth shutter blades by a primary latch prior to the initiation of theescapement movement in order to eliminate the possibility of releasingthe secondary shutter blade of a guillotine type shutter by impact dueto inertia of the lever for effecting the release of the secondary latchif the camera receives a blow or is subjected to unusual movement. Thisobject of the present invention is achieved by transferring control ofthe secondary blade from a primary latch to a secondary latch afterinitiation of the escapement movement.

Another object of the present invention is to combine a shutter camerawith a photo-flash switch so as to close the switch a preselected timeinterval before the opening of the light apertures for film exposure,and to open the switch after the exposure to permit safe replacement ofa flash bulb.

Another object of the present invention is to combine one contact bladeof a synchro-switch with the escapement mechanism in such manner thatthe spring tension of the contact blade helps accelerate the escapementas the shutter is tripped, but will be expended before actual opening ofthe shutter in order to preserve the shutter timing calibration.

The foregoing and other objects and advantages of the present inventionwill be more readily understood from inspection of the accompanyingdrawings taken in connection with the following specification, whereinlike numerals refer to like parts throughout.

In the drawings:

Fig. 1 is a plan view looking down upon the top of a stereoscopic camerahaving the present invention incorporated therein;

Fig. 2 is a View in elevation of the rear surface of the camera;

Fig. 3 is a view in elevation of the front of the camera;

Fig. i is a view in elevation of the right end of the camera;

Fig. 5 is a partially schematic view of the major portions of theshutter release and timing mechanism in set position. It is to beappreciated that various portions of this mechanism overlap but occupyvarious levels, hence some portions are drawn in skeleton outline;

Fig. 6 is a view illustrating the major portion of the shutter releaseand timing mechanism just after being released for taking a high speedexposure;

Fig. 7 illustrates the shutter release and timing mechanism just afterbeing released to take an exposure of the longest possible adjustableduration or at the slowest fixed speed;

Fig. 8 illustrates the shutter release and timing mechanism whenreleased to take a time exposure, the parts being illustrated as theywould appear corresponding to the bulb open position of a standardcamera;

Fig. 9 illustrates the shutter release and timing mechanism at thetermination of a time exposure with the parts in the position they wouldassume corresponding to the bulb closed position of a standard camera;

Fig. 10 is a partial vertical section taken substantially from the planeindicated by the line iHi (center of Fig. illustrating the exposure timeselecting mechanism, selecting knob and exposure speed dial;

Fig. ii is a partial horizontal section taken substantially along lineHH of Fig. 10;

Fig. 12 is a plan view of the escapement mechanism with the timer camsillustrated in dash line [or the purpose of clarity;

Fig. 13 is a plan view looking down upon the trip mechanism, along theline i3i3 of Fig. 14, with all other parts eliminated for clarity;

Fig. 14 is an end elevation taken from the plane l4-M of Fig. 13;

Fig. 1-5 is a plan view illustrating the reset mechanism with the partsillustrated in the set position corresponding to Fig. 5;

Fig. 16 is a view similar to Fig. 15 showing the reset mechanism afterthe shutters have been tripped, the parts being shown in positionscorresponding to Fig. 6;

Fig. 17 is a similar view showing the reset mechanism in operation toreset the shutters and shutter release mechanism, with various partsshown in dotted line at the commencement of a resetting operation and infull line in the course of a resetting operation;

Fig. 18 is a rear view of the front shutter blade;

Fig. 19 is a rear view of the rear shutter blade;

Fig. 20 is a similar view showing the shutter blades superimposed and inthe positions they occupy at the end of a resetting movement with theresetting mechanism corresponding to the position shown in full line inFig. 17;

Fig. 21 shows the shutter blades in the positions they occupy when thecamera is set, with the resetting mechanism in position corresponding tothat illustrated in dash line in Fig. '17;

Fig. 22 illustrates the shutter blades in the positions corresponding tothe commencement of a time exposure;

Fig. 23 illustrates the shutter blades in the positions they occupy atthe end of an exposure and prior to the operation of the reset mechanism;

Fig. 24 is a vertical section taken through the shutter blades and theshutter blade case substantially along the line 2424 of Fig. 15;

Fig. 25 is a partial vertical section on an enlarged scale takensubstantially along the line 25-25 of Fig. 24;

Fig. 26 is a plan view of the synchro-switch with related mechanismshown in skeleton outline; and

Fig. 2'7 is a partial bottom view showing the synchro-switch adjustmentscrew.

Although all portions of the mechanism herein disclosed function inconjunction with each other various portions thereof will be separatelydecri'oed in order more clearly to understand the operation of thecamera. These portions will be set aside under appropriate subtitles.

Shutter release and timing mechanism The shutter releasing and timingmechanism is mounted upon and between a pair of plates, the bottom platel5 of the camera and an intermediate plate i453. The plate M3 is mountedupon a plurality of bosses i5 i extending upward from the bottom plate65, so that there is a space between the plates. A primary shutter latch9 is mounted on the upper surface of plate i 43 and a secondary shutterlatch if: is mounted on the lower surface or" plate M3. The latchesextend beyond the plate a sufficient distance to engage in slots ifitand Hi (Fig. 20) of the front and rear shutter blades. The shutterconsists of a pair of shutter blades i and 3 movable from left to rightby shutter blade springs 2 and 4 respectively (Fig. 24'). When theshutter blades are set at the left of their travel the; latch. 9 holdsthem in thisposition, atwhich position apertures I36 in the rear bladetarealigned with the. lenses 98 and 59, but light is prevented fromreaching the film by the blade I whose apertures I35 are to the left ofthe lenses and not in. line with them. The latch I-El is-normally lockedby the latch pawl H which is also pivoted beneath plate I43. The shutterblade I never bearsagainst latch I0, and blade 3 normally does not bearagainst latch Ifl, which is a secondary latch or a timing latch. LatchIE! is released from latch pawl I! through the operation of a main lever8' (Figs. 5. to 9) which may be unintentionally moved due to impact oinertia effect, thus causing: the second. ary latch pawl II to move outof engagement with the secondary latch. I l, but as soon as such atransient phenomenon has ceased thelatch III is again retained by thelatch pawl H. Alight spring I39 holdslatch. II] in a counterclockwisedirection to be engageableby pawl I'I. Latch 9 normally holds bothshutter blades I and 3. Latch 9 is also lightly urged counterclockwise:by a spring I38. When latch 9 is released, as will presently appear. thestronger spring 2 operating upon the blade I causes latch 9 to be movedin a clockwise direction to release blade I, which thereupon moves so asto bring its apertures I35 in line with the lenses, and since theapertures I36 in blade 3 are in line with the lenses light is permittedto reach the film. Latch It] has now engaged blade 3 due to its havingbeen released by latch 9 and moving slightly to the right.

Latch ID will be released at a later period, as will appear, so as tocause the apertures I36 to move to the right beyond the lenses, thuscutting ofi the light from the film. It may be seen that the timing ofreleasing latches 9 and I times the exposure of the film.

The latch 9 is retained in latching position by a hook 280 on a primarylatch pawl I34 is pivoted for convenience on a timing cam shaft 49. Theprimary latch pawl I34 extends toward the right end of plate I43 andcarries a lever drive pin 46 at its right end which extends downwardthrough an irregularly shaped opening ZUI in the plate I43. The primarylatch pawl I34 also extends toward the left end of plate I43 and isprovided with an offset extension which carries a primary latch pawlreset stud 51. When the primary latch pawl I34 moves counterclockwiseabout its pivot 49, the hook 2% moves out of engagement with the latch Qto permit the shutter blade I to snap toward the right.

The latch pawl 93.4 is retained in the position illustrated in Fig. 5,which is in set position, meaning that the camera is set to take apicture. In this position its right end is engaged by the downwardlyturned end of a releaselever pawl I3 pivoted on a release lever pivot202 mounted on plate I43. The release lever pawl is provided with adownwardly turned tab 293 which engages a shoulder on a release lever I5extending toward the right of the plate I43 and pivoted at 202.

The left end of lever it extends over plate I43 and has a tab 254passing through a hole 205 in the plate 43. A release lever spring I51tends to hold the release lever in the position illustrated in Fig. 5.When the lever 56 is shiftedclockwise to the position shown in Fig. 6the shoulder thereon engaging the tab 283 rocks the release lever pawlI3 from engagement with the end of primary latch pawl I34. A strongspring I4 having one end embracing a stud 201 on plate I43 is tensionedabout timing cam shaft. 49 and hooked around the lever drive pin 46 onthe: primary latch pawl I 34., When the release lever I6; is; thus movedout of the way the spring M moves the primary latch pawl I34 in acounterclockwise direction. After it moves far enough the hook. 200 isdisengaged from the latch 9 and the shutter blade I snaps to the right.It is to be appreciated that, since the shutter blades are not shown inFigs. 6 to 9 inclusive, the latches 9 or Ill, as the case may be, arenot correctly illustrated in some cases since they should be rockedclockwise by the shutter blades. The reason for illustrating the latchesas shown is to emphasize the timing action of the release mechanism.

In order to release the secondary latch Ill means are provided to rockthe secondary latch pawl II counterclockwise about its pivot against thetension of a spring I46. Such means oomprises. a. hook provided on thelower surface of the left end extension ZIG of main lever 8 whichnormally bears lightly against the end of release pawl I I or may floatadjacent thereto. The left end 2H1 is twisted to lie in a verticalplane, so that after releasing pawl II it bears against the edge ofplate I43. The lever B is a floating lever not. having any fixed pivot.It is mounted beneath the plate I43 and is pivoted to the primaryrelease pawl I3 by' means of the lever drive pin 46 extending throughthe plate clearance hole I.

Motion. of pawl EM and main lever 8 is. trans mitted to the escapementby a main lever slot I48 engaging a sector stud mounted upon andprojecting upwardly from a sector gear 24 carried by a sector gear pivotMl" journalled in the two plates !5 and I43.

The other mechanism for controlling the manner of movement of the mainlever 8 comprises a timing cam is splined to the timing cam shaft 49.The timing cam has a major radius portion I56 (Fig. ll) extending for afew degrees. This is followed by a slight step I5! which marks thecommencement of a spiral surface I52, extending for substantiallythree-fourths of the periphery of the cam. This is followed by a furtherstep leading to a minor radius E56 extending for a few degrees, thepoints of minor and major radius being joined by a straight surface. Therelative position of cam 42 may be fixed by rotating the shaft 49, thedesired location thereof being indicated by dial as will presentlyappear.

The sector stud 25 engaged in slot Hi8 acts to translate the relativelylinear motion of slot I48 to rotary motion of the sector gear 24. In sodoing the movement of the right end of main lever 8 is retarded due tothe drag of an escapernent mechanism driven by the sector gear 25'. Thestud and slot $48 may be called a flex ible coupling. The direction ofmovement of any portion of main lever S is determined by the movement ofpin it and the adjustment of cam 48, but the time interval betweenrelease of latches 9 and II is determined by the speed. of movement ofsector gear 24 and the setting of cam 48.

When the major radius portion I of cam 48 is positioned at a desiredpoint, such as illustrated in Fig. 6, it is in position to engage a mainlever fulcrum I49 provided. on the main lever 8. In this positionrelease of the primary latch pawl I34 and slight counterclockwisemovement of the primary latch pawl causes release of the secondary latchis prior to release of the primary latch 9. This is brought about asfollows:

The spring Id urges the pin 46 counterclockinterval can". to shafportion ltd. Sligl counterclockwise rotation of pawl its rocks the mainlever 8 about its fulcrum i 39 to cause the extension 2W to strike pawlH and release latch it) due to the force of spring it being greater thanthat of spring Hi5. Thus, with this adjustment of cam 43, the latch ii}never holds either shutter blade. The timing of the mechanism is suchrelease pawl li clears the latch slightly before the hook clears thelatch ii. As soon as the hook 2T3 clears latch ii the springs 2 l causemoverent of the shutter blades 5 and 3 since neither latch restrainsthem. The springs 2 and i are of substanti l equal strength operateagainst substally equal load so that the shut-- ter blades l and 3 moveat substantially equal speeds across the lenses. The exposure will,therefore, be very fast inasmuch as the apertures I35 and 36 flash pastthe lenses, the extent of exposure being controlled entirely by the overlapping of the apertures as they move past the lenses. (Fig. 21.)

When the cam 48 rotated to a slight extent counterclockwise from theposition shown in Fig. 6 the beginning of the spiral B52 is presentedfor engagement with the fulcrum Me. In such case the movement of mainlever B to contact the release pawl ll and release .e secondary latch itoccurs after the hook 2% has released the primary latch 9. This is dueto the delayed engagement of the fulcrum i i-9 and the cam face 152which permits the lever 8 to rock about fulcrum Hi8 and contactsecondary latch pawl ii only after hook Bill: has released primary latch9. The motion of main lever B is retarded by the sector gear studengaging the main lever slot M8, pin rotating the sector gear and itspivot E l'l and driving a ratchet 236 through a ratchet pinion 25 (aswill be explained later). The ratchet mechanism provides means forslowing the movement of the sector gear so that an interval of b-1119 isprovided between the release of latch and the release of latch it. Theradius of cam is at this position is such as to permit the hook torelease latch 9 before the lever extension stril es release pawl II torelease latch ill. Thus the latch s releases both blades, blade 1continuing to its end position where its apertures uncover the lenses,blade 3 moving first into contact with latch it after a time intervalmoving to its end position. The exposure time interval may be increasedto a maximum continuously adjustable position almost to the limit of thespiral i552.

When the cam has been rotated to the posi tion illustrated in 'l', anotch 2st in a long is brought into alignment with a cam follower end233 on a long interval lever 28 ,s. 16, l1, 12). As will be explainedlater, this action brings a long interval p wl into engagement with theratchet in addition to an escapement pawl 27 which normally engages theratchet Thus gear at must overcome the slowing eifect of the two and 29as the lever it i driven by spring .5 throtgh n 33 from its set positionto a position w?" e as fulcrum 5 3.; bears against the cam 18 to causethe extension 2m to release the secondary latch Hi. When the cam 48 isin this position at the smallest end of the spiral i52 long interval. offixed duration elapses between the release of shutter blade i and therelease of shutter blade 3.

When the cam 48 is rotated to the position shown in Fig. 8 the minorradius l55 is presented to the fulcrum M9, this minor radius being suchthat the lever 8 never comes to bear against cam 48 and movement of thesector gear 24 is arrested by the gear 24 striking a boss 154 before anytension can be brought to bear by extension 2N} against pawl H torelease the secondary latch it. This condition will remain static aslong as the release lever 16 is held in its depresed position. Thisposition corresponds to the bulb poition of a camera and continues aslong as the lever I6 is held depressed. Upon release of the lever l6spring l5! causes the lever It to move counterclockwise. The lever 8 isfloating in a position such that a main lever stud 53 thereon is nearthe upper end of a slot 255 in the plate [43 and is in position to bestruck by the tail 8!) of lever 16 (Fig. 9). The movement of the lever 8through this medium is sufficient to cause the extension 216 to releasethe secondary latch it and cause the blade 3 to end the time exposure,this action corresponding to the closing of a camera shutter by a bulbtime exposure mechanism.

I thus have, through the same sets of parts, means for instantaneousexposure, means for infinitely variable fast exposure, means for a set,long exposure, and means for a manually controllable time exposure oflengthy extent.

Exposure speed adjustment Figs. 10 and 11 show the arrangement of thecams 6'! and 28, the shaft 19 and a knob 142 together with an exposurespeed dial Ml, the latter two items being visible in Fig. 1, from whicha more comprehensive idea of the location of the adjusting knob may beobtained. It will be seen from Fig. 10 that the extreme lower end ofshaft 49 rests in a cavity 228 in the bottom plate l5 and its upper endpasses through a suitable opening in the top plate 22l of the camera.The lower end of the shaft is splined to receive cams 4'! and $8 andhold them against relative rotation with respect to each other and theshaft 59. A collar 222 is mounted on the shaft to hold the cams againstendwise movement against the thrust of a friction washer M5 which tendsto hold the assembly in its adjusted position. Immediately above thewasher M5 the shaft is provided with a step enlargement which isjournaled in an opening in the mounting plate I43. Immediatelythereabove the shaft is provided with a second step that journals theprimary latch pawl I36, which is retained in position by a third step inthe shaft. The upper end of the shaft carries a hub 223 which isfastened to the shaft by a set screw 224, and the dial H is fixed to theupper surface of the hub 223. The periphery of the dial carries figuresand indicia on its upper surface which are visible through the arcuatewindow M4. The upper end of the shaft, after passing through the topplate 22L is keyed to enter a key socket in the knob M2 which isretained in position by a screw 225 threaded into the end of the shaft.Rotation of the knob M2, therefore, rotates the cams ll and 5S, and theextent of rotation thereof is indicated by the dial indicia passing anindex point 225 on the upper surface of the plate 22!. The indiciacarried on the dial Ml indicate the fraction of a second of exposure, orother information relating to the exposure speed.

Escapement mechanism Fig. 12 further relates to the mechanism disclosedin Figs. to 11 inclusive in that it discloses the complete escapementmechanism including the sector gear 24. In this figure, for clarity ofillustration, the mounting plate Hi3 and the cams 3! and at are shown indash outline. It will be seen that the sector gear 24 engages with theratchet pinion 26 which is fastened to the upper surface and concentricwith the escapement ratchet 2355. When the portion of cam 66 includingthe major radius I50 and all but the minor radius is in position toengage the fulcrum hill of the main lever 8 only one of two ratchetescapement pawls is engaging the teeth of the ratchet to slow themovement of the sector gear This primary escapement pawl is indicated bythe numeral 2?. It may be seen that the teeth thereof engage the teethof the ratchet 236 and permit their release in timed steps rather thanin a continuous uninterrupted movement. This type of escapement is wellknown in the art.

When the cams 48 and 37 are turned to permit the fulcrum point Hi9 oflever 8 to engage the cam at a radius but slightly larger than thesmallest radius portion of the spiral I52 the exposure is at a maximumtime exposure of fixed duration with the shutter closing automaticallyat the end of the time. This is accomplished by mechanism disclosed inFig. 12 in the position disclosed in Fig. 12. It will be seen that thelong interval escapement pawl 29 is pivoted at 23| beneath one arm ofthe long interval lever 28 which is pivoted on a boss in plate i5 andsecured with a screw 232 threaded into the mounting boss. The far end ofthe lOng arm of lever 28 is provided with cam follower end 233 which isadapted to engage the long interval notch 234 in cam 41. Thus the longinterval escapement pawl 29 is brought into engagement with the teeth ofthe ratchet gear 230 by a tension spring I53 extending between the crankarm 235 of lever 28 and a boss 235 extending upward from the bottomplate !5. The arm 235 is urged against an eccentric screw 4 35!, whichmay be rotated to adjust the engagement of pawl 29 with ratchet 2311.The ratchet gear 230 now has to overcome the inertia of the pair of'pawls 21 and 29 rather than the single pawl 2'3 during the movement ofthe sector gear 24.

When the shaft 49 is rotated in either direction from this position thelong interval escapement pawl 29 is removed from engagement with theteeth of the ratchet gear 239 and the ratchet gear has to overcome theinertia of the pawl 2'! only, therefore the length of time required forthe main lever 8 to pivot about the cam 48 is controlled entirely by thesingle escapement pawl 21. In this position the back of pawl 29 engagesa pair of bosses 23! preventing the pawl from rocking into'engagementwith the ratchet 230.

Trip mechanism Referring to Figs. 5, Band 14 there is disclosed meanswhereby the release lever I6 is moved fromthe position illustrated inFig. 5, the set position, to the position illustrated in Fig.6, the

release position. This mechanism comprises a shutter release button I33which is located in and projects above an opening in an extension of thetop plate 22! indicated by the numeral 249. The button 833 is providedwith a flange 24! limiting outward movement of the button. A buttonguide pin 242 extends downward into an moving counterclockwise.

opening in a boss 2&3 rising upward from the bottom plate I5. The pin242 passes through an opening in the short arm of a trip lever 244 whichis mounted upon a pivot 245 pressed into the frame of the camera. Thebutton 433 rests upon the horizontal short arm of lever 2 16, which isnormally restrained in its uppermost position by the spring engaging thetall of lever I6 (Fig. 5). The long right end of lever it is providedwith a rounded knoblile projection 246 which engages the lower extremityof the vertical long arm 26? of the trip lever. A screw 248 is threadedinto the portion 240 of the top plate and is removable to permit theattachment of a standard release cable. Counterclockwise rotation oftrip lever 24 i is limited by the interference of shutter case plate 5with arm 241. It may be seen from the foregoing and the description ofthe mechanism in Figs. 5 to 12 inclusive that when an accurately fastexposure is desired the button l33 is depressed, which. action willcause release of both the shutter blades. When a manually controlledtime exposure is desired the button 33 is depressed, but due to theinability of main lever 8 to release the secondary latch II], the filmwill remain exposed to the light until button 33 is released, whereuponspring I51 will cause lever Hi to return to its set position and in sodoing cause the tail 8!] to engage the main lever stud 158 to releasethe secondary latch and end the time exposure.

Reset mechanism Figs. 15, 16 and 1? illustrate the resetting mechanismfor the camera. Fig. 15 should be studied in conjunction with Fig. 5,which, it will be recalled, illustrates the mechanism in the setposition with the rear shutter blade having its apertures in front ofthe lenses and the front shutter blade held with its apertures to theleft of the lenses by the latches 9 and I 0. In this position therelease lever pawl i3 is holding the primary latch pawl I3 5. The tab203 is resting against the elbow of the release lever l6. The

. opposite face of the tab 203 engages the tip of an arm 250 on a resetstop pawl 15 which is pivoted at 26! to the camera frame. A spring 18 is'tensioned around the pivot 26! and has one end engaged against the rearplate 262 of the camera and its opposite end hooked over the rear edgeof the reset stop pawl 75. The spring 18, therefore, urges a reset stoppawl tab 263 into engagement with a reset cam notch I30 provided in thesurface of a cam H9 which is mounted upon a pivot 2% extending upwardfrom the bottom plate 15. When the release lever I6 is rocked to theposition illustrated in Figs. 6 and 16 the release lever pawl I3 isrocked clockwise and the tab 293 rocks the reset stop pawl clockwise todisengage it from the cam notch I30 against the tension of the spring18. The release lever pawl 53 is provided with a downwardly extendingtab 26? which engages an arcuate face 268 on the right end of primarylatch pawl [34 which is Therefore, as long as the primary latch pawl isreleased the reset stop pawl l5 cannot i e-engage the reset cam notchThe reset cam I i9 is fixed to a large reset gear l9 which meshes with asmall reset gear 36 iounted upon a shaft 33 extending from the bottomplate it? through the top cover and which has fixed. thereto a resetknob 40 (Fig. 1). The reset knob may now be turned counterclockwise andthe resetting of the shutter mechanism will 11 be accomplished in onecomplete revolution of the reset gear 19.

In Fig. 15 will be seen that the latches 9 and Hi project through a sloti'iil in a rear shutter case plate and project toward a parallel frontshutter case plate 8. The latches S and ill engage the shutter blades land 3 which lie between the plates 5 and 6. When the latches 9 and illare released they may pivot clockwise to permit the shutter blades tomove from set position at the left end of the slot between the plates 5and 5 to their released position toward the right end of the slot.

The rear shutter case plate 5 is provided with a slot 2'! i, the loweredge of which is pressed rearwardly to form a guide rail 212 extendingrearwardly from the surface of the plate 5. The guide rail H2 is engagedby a downwar ly turned tab 213 on the end of a reset lever 35, the tipof which, adjacent tab N3, is provided with a reset crank finger 2'24projecting into the space between plates 5 and 6 and engaged in slots 1%and ltd in the shutter blades. The reset lever 35 overlies the shutterrelease mechanism and extends toward the right end of the camera whereit is pivoted upon a pin 2l'5 projecting upward from the face of gear19. When the camera is set lever 35 occupies the position illustrated in15.

The slots led and I64 in the shutter blades, as will presently appear.are of such length that upon termination of the exposure the le-t ends ithe slots in the shutter blades are closely adjacent the finger 22M onthe reset crank. As soon as the exposure is completed, the release leverH5 is returned to its initial position, as indicated in Fig. 15,permitting the tab 26'! of release lever pawl l3 to bear against theface 258 or" pawl I34 by action of a spring 2% hooked over a tab 2M onlever it, tensioned around the hub of pawl 13, and hooked over the edgeof pawl it. This readies the release lever pawl 13 to latch the primarylatch pawl i3 5, but due to the engagement of the tab 23? with the face268 (Fig. 16) it may not do so, and the reset stop pawl 75 is held ininopera tive position.

In Fig. l? the primary latch pawl l34 is shown in dash lines at the endof its movement corresponding to the illustration in Fig. 8, with therelease lever pawl [3 still held in clockwise position. It is also seenin this figure that the release lever l5 has returned to its initial.position and at the termination of the exposure the reset lever 35 (indash lines) still occupies the reset position with its finger 274 at theright end of the guide rail 2112. In this position the primary latchpawl reset stud 5'? lies closely adjacent an edge of a portion of thereset lever 35. The operator now turns the reset knob 4%counterclockwise, thus rotating the reset gcar ls clockwise. The resetlever 35 is thus caused to bear against the stud 57 to rock the pawl i34clockwise. As will be recalled, this causes repositioning of the sectorgear 26 and the main lever B to their set position due to theinterconnection of those parts. During all of this time the reset stoppawl i5 is held from engagement with the reset cam H9, except for abrief interval when it is moved still farther clockwise as the tab 283rides over the cam lobe 271?. A. reset crank offset MB engages theprimary latch pawl reset stud 5'. (Fig. ll) as the gear l9 completessubstantially one-half of a revolution, whereupon additional rotation ofgear 19 causes reset lever 35 to move the primary latch pawl reset studto the 12 position it occupies when the primary release pawl 134 is inits set position. The reset lever 35 now begins to move away fromengagement with the stud 5 but the pawl tilt is retained in set positionby the release lever pawl 13 which has been moved counterclockwise byspring 25). Spring is now brings reset stop pawl to bear against theface 21s of cam I it) which is of greater radius than the bottom of thenotch lad. The remaining semi-revolution of gear is merely returns thereset lever 35 to its position toward the right of the camera until thetab drops into the notch HQ. The lobe 2TH is provided on the cam Heimmediately beyond the notch 333 which has a sloping face engageablewith a regulating lever '54 associated with the film advance mechanism.Lobe Zll and a relief 2*3 on the cam face 2'56 are incidental to theshutter reset operation.

Shutter blades Figs. 18 to 25 inclusive illustrate the shutter bladesand their operation. In Fig. 18 there is disclosed the front shutterblade 5 which is provided with a pair of apertures 135 having their leftends rounded and of such diameter as to permit the passage of lightthrough the lenses without interference. The shutter is provided with along slot 550 toward the left end, a short slot Isl near the center, andan edge slot i52 extending from the right of the center line toward theleft end. An end notch i6! is provided in the lower right corner. Therear shutter blade 3, as disclosed in Fig. 19, is provided with a pairof apertures i353 having their right ends rounded and of the same radiusas the rounded ends of apertures 535. The apertures 35 are substantiallyrectangular beyond the rounded ends and are longer than apertures A 164is adapted to overlie the slot let. A slot is in horizontal alignmentwith the slot llii and an edge slot let is in horizontal alignment withthe slot I62. The upper right corner is provided with an end notch I88.

In Fig. 20 the blades I and 3 are shown in their relative position whenpushed by the reset ever 35 to the left end of the channel they occur:tween the blade case plates 5 and 6. It will be seen that the finger Eli on the reset lever has engaged the left ends of slots H and I to pushthe blades completely to the left, which position corresponds to Fig.1'? illustrating the action of the lever (refer to solid lines of lever35).

Tips of the latches 9 and It bear against the plates as the plates slidepast them from right to left until the appropriate slots receive them.The light spring I38 urges the latch 9 into the slots i6! and itl, andthe light spring i39 urges the latch 10 into the slots I32 and MB. Thisreadies latch 9 for engagement by primary latch pawl I34 and readieslatch I!) for engagement by econdary latch pawl l I. It will be recalledthat the offset I40 on reset lever 35 will now reposition the pawl I34and associated mechanism so that hook 209 will engage the tail of latch9. Repositioning of primary latch pawl I34 will rock the main lever 8clockwise to move its portion 2 H1 away from the tail of latch pawl llpermitting spring M8 to return the pawl i into engagement with latch [8.

As soon as the pin 215 passes beyond dead center and substantiallycoincidental with the latching just described the reset lever 35 startsto retract. It will be observed in Fig. 20 that latch 9 is positioned inthe left end of slot I57 which effectively prevents movement of the rearblade 3 as urged to the right by its spring 4. Latch 9 is at the rightend of slot 161 so that the front blade I may move toward the right asurged by its spring 2 until it engages latch 9 (Fig. 21). The blades aretherefore both held tensioned in the "set position while the finger 2Mretracts to the far right end of the slots I60 and I64 as the reset camgear 19 completes its revolution to the position illustrated in Fig. 15.The blades are now in the set position with the camera lenses uncoveredb the apertures I35 but covered by blade I whose apertures I35 are stillto the left of the lenses. The blades are held in this position by latch9 and it will be noted (Fig. 21) that latch Ed is slightly spaced fromthe left edge of slot E58 and is greatly spaced from the left edge ofslot 562. Latch It) is preferably spaced about of an inch from the leftedge of slot ififi so that when the camera is set all of the bladerestraining force is provided by latch Iii which is held by positivelyretained mechanism including the lever rat and the pawl I3. Thus, ifshaking, o-r jarring, or dropping of the camera occurs to such an extentas to cause the main lever 8, or other connected mechanism to movesufficiently to release the secondary shutter latch pawl Ii, thesecondary latch I6 nevertheless remains in operating position and willbe re-engaged by the pawl iI immediately after the transientdisturbance.

If an instantaneous high speed exposure is desired and the fulcrum pointI49 engages the major radius the cam 43 to disengage the secondary latchit prior to disengagement of the primary latch a soon as latch 9 isreleased there will be nothing to restrain the blades against movementto the right due to the effect of their springs (to be disclosed later).The two blades, therefore, flash past the lenses and expose the film atthe highest speed possible, the duration of exposure being controlled bythe length of the slots provided by the overlapping ends of theapertures I35 and iSB and the fixed tension of the springs 2 and 4.

If, on the other hand, an exposure of fixed duration of adjustableextent is required and the cam 48 has been positioned to present itsspiral surface 852 to the fulcrum M9, the secondary latch iii will beretained until a variable length of time has elapsed after latch '5 hasbeen released. This action, illustrated in connection with 7, is furtherillustrated in connection with It will be noted that latch 19 has beenreleased first, thereby permitting the front blade i to spring entirelytoward the right end of the camera until it is restrained from furthermovement at which point the rounded ends of the apertures 535 correspondwith the rounded ends of the apertures I3E to provide a circular openingpermitting the passage of light to the film. With the release of latch 9by pawl IN, the movement of blade i pivots latch 9 clockwise against thetension of its spring i353, and the tip of latch Q lightly pressesagainst blade I. Latch I0, how- -ver, is still held by the latch pawl Hand enages and prevents the rear blade 3 from movng more than thedistance necessary for the left edge of slot I68 to engage latch Iii, aspreviously noted about of an inch. However, this slight movement doesnot affect the light transmitted as the extended apertures I36 requiremuch more movement to enter the light path. Nor does this slightmovement affect the timing as the movement is concluded before bladeun-- cove-rs the lenses. The primary function achieved by holding theblade 3 with latch 9 and not by latch iii, except when an exposure hasbeen initiated, is to provide a locked mechanism protected from shock toinsure dependable operation when it is initiated. Dependent upon thepositioning of the spiral Hi2, an interval of time elapses before latchiii releases the rear blade 3. When blade 3 is released it springs tothe right to the position illustrated in Fig. 23, causing the aperturelit to move beyond the apertures E and thus terminate the exposure.Movement of blade 3 rotates latch l8 clockwise against the tension ofspring ass, and the tip of latch iii presses lightly against blade 3.

When a manually controlled time exposure is desired corresponding to theactions illustrated in Figs. 8 and 9, the primary latch 57 is firstreleased, as shown in Fig. 8, but due to the fulcrum I49 being oppositethe minor radius portion I58 in cam 48 the main lever 3 cannot releasethe sad ondary latch ill. The blades will, therefore, rest in theposition illustrated in Fig. 22 as long as the release button N53 isheld depressed. When the button is relinquished release lever It yieldsto spring I 51 and the portion fill of the release lever l6 strikes themain lever stud Hits to release the secondary latch Ill and complete theexposure.

Shutter blade pads and springs At the right end of the slot betweenplates '5 and B there is provided a pair of pads of shockabsorbingmaterial, such as a pad formed of inch thick velum paper. There is a padI59 ad jacent the upper corners of the blades and a pad ill! adjacentthe lower corners of the blades. It will be noted that the blade 5 hasits end notch I6! in such position that the blade i is prevented fromstriking pad I'iil and only strikes the upper pad 169. Similarly notchM53 in blade 3 causes blade 3 to strike the pad Vii only. This spacingof the pads and having them substantially independent of each othertends to eliminate the possibility of shutter bounce of such an extentas to uncover the lenses after termination of the exposure. If the twoblades struck the same pad there would be the possibility of the timedblows setting up sympathetic vibrations to such anextent as to bouncethe rear shutter blade 3 back sufliciently to uncover the lenses.

In Figs. 18 and 19 it will be seen that blade I is provided with a wideslot ltd which has a narrow extension I ill at its top extending towardthe left of the blade. At the shoulder formed at the beginning of theextension l8i there is provided a hole I82. The rear blade 3 has a slotI83 of substantially the same length as slot 338 and'a short extensionHid at its lower left corner adapted to overlie the hole I32 in blade i.Just above the extension I 84 there is a small hole I85 adapted. tooverlie the beginning of the extension I8! in blade I.

Referring to Fig. 24 it will be seen that the front shutter blade caseplate 5 is provided with an embossed ridge I81 and a lower parallelridge I88 which extend inwardly into the space between the case plates 5and 6. The rear plate 5 is provided with matching ridges I89 and E90respectively. The adjacent surfaces of the ridges define guides for theshutter blades I and 3. Below the lower guides there is a wide spaceprovided by stamping the plates outwardly and the slots I80 and I83 inthe shutter blades lie within this wide space. In Fig. 25 it will beseen that a tongue l9I is stamp-ed inwardly from plate 5, the tonguebein provided with a pair of holes I92 vertically spaced the samedistance as the distance between the holes I82 and I85 in the shutterblades. The spring 2 which operates the front shutter blade extends fromhole I82 to the lowermost hole I92 and the spring 4, which operates therear shutter blade 3, extends from hol I35 to the uppermost hole I92.The springs lie within the slots I80 and I83 and do not bear againsteither shutter blade at any point except at their connecting ends. Theends of the springs passing through the holes I82 and I85 extend intothe extensions I84 and I8I respectively at certain periods of theshutter operation. Fig. illustrates the springs 2 and 4 extended as theywould appear when the shutter blades are in set position toward theleft. When blade I moves toward the right the hook on spring 4 is stillclear of the front blade due to the extension I8 I.

There are thus provided operating springs of equal length which may beformed so as to have very nearly the same resiliency and which aretensioned to very nearly the same extent when the blades are set, andneither of which is subjected to frictional resistance by bearingagainst any other part. When the high speed, or fastest, exposure isdesired the two blades are released simultaneously by the latch 9 andflash past the lenses, maintaining, because of the matched springs, theaperture slot seen in Fig. 21. When an adjustably longer exposure isdesired latch II] releases blade 3 at a timed interval after latch 9releases blade I. Therefore, the slot provided by the apertures is wideror fully opened as determined by the setting of cam 48. In mostinstances the speed of the blades is sufficiently great to permit bladeI to complete its movement and come to rest before blade 3 starts tocover the lenses.

Synchro-swz'tch In Fig. 5 it will be noticed that between the latch I0and the latch pawl II there is an opening through the intermediate plateI43 through which a tab 32 projects to engage a shoulder I59 on theprimary latch pawl I34. In Fig. 26 it will be seen that this tab 32 ismounted on the free end of a short spring contact blade 3 I. The springcontact blade 3| is retained by screws 330 against the side of aprojection SUI rising from the bottom plate I5. Insulators 3H2 insulatethe switch blade 3I from the screws 3% and the rear surface of the bladerests against a strip of insulating material 303. outer surface of along switch blade 30 which is also insulated from the screws 333 by theinsulators 302. It in turn rests upon a strip of insulating material 304positioned between it and the projection 30 I.

The lower end of the tab 32 is mounted to blade Si by a silver contact3125 which is in alignment with a silver contact 39% mounted on the longblade 33. The blade 33 continues on beneath the plate I43 and bearsagainst an eccentric screw 23 rising upward from the bottom plate I5.

By adjusting the relative position of the eccentric 23 the contacts 305and 386 are positioned at an adjustable distance fromeach other when thecamera is in set position, as seen in Fig. 26, with the pawl I34 latchedin position as in Fig. 5.

A wire 3H) is soldered to blade BI and a wire 3H is soldered to blade33. The two wires are passed through an insulating sheath BIZ whichpasses forward to a position below and between the lenses where thewires 3H; and 3 are connected to terminals and 3M respectively, whichpass through, but are insulated from, the bottom plate and are inposition to receive wires (not shown) leading to a flash bulb socket andThe strip 3G3 is mounted on the 16 means for applying voltage to theflash bulb when the contacts 395 and 3525 are brought together.

When it is desired to take a flashlight picture appropriate standardbulb and battery accessories are connected to terminals 3 i 3 and (H 4preparatory to flashing the bulb by closing contacts 335 and 3355. Thefilm is exposed by pressing the button I33 (Fig. 14). Downward motion ofthe button I53 moves the release lever I6 through the action of the triplever 244. The tail 353 and the bent-down tab 2 3-! (Fig. 13) normallyhold the long switch blade to away from the eccentric screw 23 to aposition sufficiently far from blade BI that the contacts 395 and cannottouch regardless of the position of other cooperating elements. Initialmovement of lever I5, and hence of tab 2%, perm the blade 38 to yield toits inherent tension and come to rest in its active position againsteccentric screw shown in Fig. Additional movement of lever it releasesthe primary latch pawl 234 which starts to rock counterclockv-Jise asdescribed previously. Very slight angular movement of pawl I34 from itsnormal set position moves the shoulder I59 sufficiently to permit blade3I to yield to its inherent tension and bring contact 385 againstcontact 366. Additional movement of pawl I34 releases latch 9 andshutter blade I as described previously. The relationship between hook233 and shoulder I59 is preferably such that contact 365 is brought tobear against contact 3% approximately /50 of a second before hook 289releases latch S for most flash bulbs. In this manner the flash bulb isignited and permitted to come to full intensity of light before theopening of the lens apertures. Adjustment of the position of eccentric23 by an attached slotted head 301 permits the /50 second interval to bevaried as desired. Preferably the head 38? extends through the bottomplate I5 in order that such adjustment may be made from outside of thecamera, and may be calibrated with respect to a visible scale. Releaseof button I33 (Fig. by the operator after completion of the exposureprompts spring I5! (Fig. 5) to move the lever i3 and its tab 26dcounterclockwise, returning the switch blade so to its inactive positionwith the contacts open. In this manner the circuit is rendered safe forthe operator to replace the flash bulb before resetting the shutter ifhe prefers without the danger of suffering severe burns from loadingbulbs in hot circuits.

After the latch 9 is released pawl I34 continues to the end of itsmovement and may be returned by the reset mechanism. The resettingoperation moves pawl I34 clockwise whereupon the shoulder I55; engagestab 32 and moves blade SI against its tension to the set position.

It will be noted that the spring tension of the short blade 3i on theprimary latch pawl I34 serves two useful purposes. The obvious purposeis to bring the contacts together with sufiicient pressure for reliableelectrical contact when the primary latch pawl I34 perm-its the contactsto come together. The second and obscure purpose is to apply additionalstarting torque to the primary latch pawl I34. This is accomplished dueto the tab 32 pressing against the shoulder I59 and tending to rotatethe pawl I34 in the same direction that it is forced by the spring i4,and this additional force increases the acceleration of the escapement,or, in other words, aids in overcoming the inertia of the escapementwhen the shutter is tripped. The torque supplied by the switch blade 3iis applied only until the contacts close which, as has been noted above,is approximately /50 of a second before the shutter opens. Therefore theforce of the spring blade 3! has no. effect on the shutter timing whichtakes place after latch ii is released. During the shutter timingperiod, i. e., fromthe release of latch 53 to the release of latch It,the only force ap plied to the escapement mechanism is that of springI6. It will be observed that there is no possibility of error due tomanual interference with the timing of the switch since the timing isaccomplished solely by the pawl i34- after the release lever [6 isoperated. The primary latch pawl I36 positively times the opening of theshutters and the flashing of the bulb since both operations are entirelyunder its control.

I have thus provided photo-flash synchronization mechanism which is notin any manner affected by the operation of the shutter release button.An operator who depresses the button slowly will have exactly the sameresult as an operator who depresses the button rapidly. It will also beapparent that the use of pigtails is eliminated both for simplicity ofconstruction and uniformity and dependability of operation.

Other mechanisms In Figs. 1 to 5 inclusive there are disclosed variousother mechanisms, at least in part. For example, it will be seen thatthere is a knob 65 attached to an exposure counter dial. Mechanismprovided within the camera rotates the dial to the proper extent eachtime that reset knob 40 advances the film. At the center of the camerato the left of knob 65 there is provided a view-finding device. To theleft of center there is a knob l2! which (1) permits rewinding exposedfilm into the daylight loading magazine; (2) permits winding apredetermined length of exposed leader past the exposure apertures foreconomical loading of fresh film; ('3) permits resetting the shutterwithout advancing the film; and (4) permits normal film advance sequenceof alternately one frame and three frames automatically. At the extremeleft of the camera there is a rewind knob ill which operates in theusual manner to rewind the strip of film material into its daylightloading magazine. In front of the window I44 there is a window throughwhich is visible a focus tape I80 having indicia for indicating thedistance from the lenses to the plane in sharpest focus. At the right ofthe window I44 there is a shield I It adapted to move across and maskthe indicia on the tape Hi9. At the left of the window I 44 there is ashield Ill having indioia thereon for indicating the f-stop of the lensirises, shield i ll also moving across and masking the indicia on tapeHill. The shields I I! and H8 are interconnected for simultaneousmovement in opposite directions when a stop selector wheel 4!!!! isrotated. The tape ii!!! is movable past an index point when a focusselector wheel 40! is rotated. The wheel 40: is rotated to focus thelenses on the subject by setting the scale reading corresponding to thedistance to the subject adjacent to the index point; the f-stop wheel isthen rotated to set the selected f-stop value of the lens irisesindicated by the f scale on shield I ll opposite its index point. Theshield H8 moves simultaneously with the movement of the shield Ill andin the opposite direction. The two shields, therefore, uncover avariable portion of the tape lhl, the limits of which define the depthof field for that focal distance and that particular stop value. Thewheel dill adjusts the front element of the lenses to focus on the filmlocated adjacent the back of the camera. The wheel Mlfl controls theopening of the irises for proper exposure under varying lightconditions. These other mechanisms briefly mentioned herein may be morecompletely ascertained from my co-pending applications, Serial No.754,962, filed June 16, 194.7, and Serial No. 754,963, filed June 16, 19:7, now, respectively, Patent No. 2,527,106, issued October 24, 1950,and Patent No. 2,515,272, issued July 18, 1950.

It is to be appreciated that the instant disclosure is with .respect toa stereoscopic camera having a pair of lenses. However, it will beapparent to any person skilled in the art that the shutter blades i and3 might have single apertures therethrough so located as to admit lightthrough a single set of lenses for the taking of ordinary photographs. Ido not intend that this patent should be limited to a stereoscopiccamera.

Having illustrated and described the preferred embodiment of the presentinvention, it should be apparent to those skilled in the art that thecombination and various portions of the combination, are subject tomodification in detail and arrangement. Likewise, some one operation ofthe herein disclosed mechanism may be utilized without utilizing theothers in cameras omitting some of the refinements of the presentcamera, or in cameras having other types of mechanism for achievingsimilar functions. All such modifications in detail and arrangement ascome within the scope of the appended claims are considered to be a partof my invention.

I claim:

1. In a camera of the type including a pair of longitudinally movableshutters each having an aperture therein and each being movable independently of the other from a set position to a released position duringwhich said shutters move relative to the lens of the camera for exposinga portion of a film in the camera, the aperture of a first one of saidshutters being aligned with the lens when said first shutter is in setposition and out of alignment therewith when in released position andthe aperture of the second of said shutters being out of alignment withthe lens when said second shutter is in set position and in alignmenttherewith when in released position whereby light is prevented fromstriking film when both shutters are either at set position. or atreleased position, said apertures being overlapped to provide a minimumopening out of alignment with the lens when. shivers are in set positionand said apertures providing a maximum opening in alignment with thelens when said first shutter is held its set position and said secondshutter is at its released position, a shutter spring associated witheach of said shutters for independently moving said shutters from setposition to released position, said shutters being movable under theinfluence of said shutter springs at substantially the same speedwhereby if said shutters are released at the same instant a minimumexposure occurs since said apertures remain in their same relativeposition during simultaneous movement of the shutters past the lens, ifsaid first shutter is released durthe movement of second shutter fromits set to its released position said apertures over 1 to a variableextent determined by the relai e position of the second shutter at theinstant said first shutter is released in order that variably timed highspeed exposures may be made, and if said first shutter is held at setposition until after said second shutter has come to rest at releasedposition timed exposures of variable duration may be made; the improvedshutter controlling mechanism comprising a manually operable part, areset lever having operative association w th both or" said shutters,crank means connecting said reset lever to said manually operable partincluding a reset lever crank pin movable through one completerevolution at each operation of said manually operable part whereby saidreset lever returns said shutters to set postion and is then returned toa position of readiness for a subsequent resetting operation, a primaryshutter latch and a primary shutter latch spring associated therewithand constantly urging said primary shutter latch to latching position inengagement with both of said shutters to hold both shutters in setposition when returned the etc, a second-- ary shutter latch and asecondary shutter latch spring associated therewith and constantlyurging said secondary shutter latch into latching position additionallyto hold said first shutter in set position when returned thereto, a prmary shutter latch pawl engageable with said primary shutter latch tohold it in latching position, means on said reset lever to move saidprimary shutter latch pawl into holding engagement "1th said primaryshutter latch, means to loclc said primary shutter latch pawl in engagedposition, primary shutter latch pawl spring means biasing said primaryshutter latch pawl toward latcl1 releasing position, a manual tripdevice including means to release said primary shutter latch pawllocking means whereby both shutters may be simultaneously released fromsaid primary shutter latch, a secondary shutter latch pawl engageablewith said secondary shutter latch to lock said secondary shutter latchin holding position, spring means biasing said secondary shutter latchpawl toward holding position, means engageable with secondary shutterlatch pawl to move the same to inoperative position whereby said firstshutter may be freed to move from set position to released positioncomprising a floating lever engageable with said secondary shutter latchpawl and including a fulcrum portion, a timing cam, manual meansconnected to said timing cam rotatively to move selected portionsthereoi into operative alignment with said fulcrum portion of saidfloating lever to vary the movement of said floating lever, andescapement means operatively associated with said floatin lever anddriven by said primary shutter latch pawl sprin means.

2. The structure set forth in claim 1 wherein said timing cam comprisesa major radius portion which, when aligned with the fulcrum portion ofsaid floating lever, causes said secondary shutter latch pawl to bemoved to inoperative position by said floating lever prior to release ofsaid primary shutter latch whereby said minimum opening flashes past thelens to effect a minimum exposure when said primary shutter latch pawlsubsequently moves to inoperative position.

3. The structure set forth in claim 1 wherein said timing cam comprisesa spiral portion which, when any selected point thereon is moved intoalignment with the fulcrum portion of said floating lever, causes saidsecondary shutter latch pawl to be moved to inoperative position by saidfloating lever subsequent to release of said primary shutter latch butduring movement of said second shutter whereby high speed exposures ofvariable extent are effected.

4. The structure set forth in claim 1 wherein said timing cam comprisesa minor radius portion which, when moved into alignment with the fulcrumportion of said floating lever, causes said floating lever to berendered incapable of releasing said secondary shutter latch pawl untilafter said second shutter has come to rest whereby timed exposures maybe effected.

5. The structure set forth in claim 1 wherein said timing cam comprisesa minor radius portion which, when moved into alignment with the fulcrumportion of said floating lever, causes said floating lever to'berendered incapable of releasing said secondary shutter latch pawl untilafter said second shutter has come to rest; in combination with manualtrip device spring return means operative to return said manual tripdevice to normal position upon manual release thereof, and means on saidfloating lever engageable with said manual trip device to release saidsecondary shutter latch pawl during returning movement of said manualtrip device whereby manually controlled timed exposures may be effected.

6. The structure set forth in claim 1 wherein said timing cam comprisesa portion of such radius that, when said portion is moved into alignmentwith the fulcrum portion of said floating lever, said floating lever isrendered ineflective to release said secondary shutter latch pawl untila fixed interval of time after said second shutter has come to rest.

'7. The structure set forth in claim 1 wherein said timing cam comprisesa portion of such radius that, when said portion is moved into alignmentwith the fulcrum portion of said floating lever, said floating lever isrendered ineffective to release said secondary shutter latch pawl untila fixed interval of time after said second shutter has come to rest; incombination with manually adjustable means to vary the speed of saidescapement means whereby selectively to vary the fixed interval of timeof release of said secondary shutter latch pawl after said first shutterhas come to rest whereby long exposures of adjustably fixed duration maybe made when said trip device is operated.

8. The structure set forth in claim 1 wherein said primary shutter latchpawl is pivotally connected to a portion of said floating lever wherebysaid primary shutter latch pawl spring means tends to cause movement ofsaid floating lever in one manner upon release of said primary shutterlatch pawl, and said escapement mechanism is connected to said floatinglever through a pin and slot connection.

9. The structure set forth in claim 1 wherein said primary shutter latchpawl is pivotally connected to a portion of said floating lever wherebysaid primary shutter latch pawl spring means tends to cause movement ofsaid floating lever in one manner upon release of said primary shutterlatch pawl, said escapement mechanism includes a sector gear, saidsector gear is connected to said floating lever through a pin and slotconnection, and said secondary shutter latch pawl spring means isoperatively associated with said floating lever at a point remote fromsaid pin and slot connection whereby said floating lever pivots aboutsaid point until said fulcrum portion engages said timing cam.

10. The structure set forth in claim 1 wherein said primary shutterlatch pawl is pivotally connected to a portion of said floating leverwhereby said primary shutter latch pawl spring means

